NLO QCD corrections to ZZ+jet production at hadron colliders

TL;DR

The paper presents the first fully differential next-to-leading order QCD calculation for $ZZ$ production in association with a jet at hadron colliders, addressing its role as a key background to Higgs and new physics signals. It combines detailed virtual and real corrections, including advanced tensor-reduction techniques and a robust subtraction framework, to produce precise cross sections and differential distributions for the Tevatron and LHC. The study finds sizable NLO effects, with reduced scale uncertainties that can be further improved by applying a veto on additional jet emissions, underscoring that NLO corrections alter both normalization and shape relative to LO. These results provide more reliable predictions essential for collider analyses and background modeling in precision Higgs and new physics searches.

Abstract

A fully differential calculation of the next-to-leading order QCD corrections to the production of Z-boson pairs in association with a hard jet at the Tevatron and LHC is presented. This process is an important background for Higgs particle and new physics searches at hadron colliders. We find sizable corrections for cross sections and differential distributions, particularly at the LHC. Residual scale uncertainties are typically at the 10% level and can be further reduced by applying a veto against the emission of a second hard jet. Our results confirm that NLO corrections do not simply rescale LO predictions.

Figures (4)

• Figure 1: Representative LO graphs for the partonic process $q\bar{q}\to ZZg$.
• Figure 2: Representative one-loop graphs for the partonic process $q\bar{q}\to ZZg$.
• Figure 3: Comparison of the scale dependence ($\mu_R=\mu_F=\mu$) of the $ZZ$+jet cross section at the Tevatron and LHC with $p_{T,\,\text{jet}} > 50$ GeV for the hardest jet in LO (dotted) and NLO (solid). For the LHC the exclusive NLO cross section when a $p_{T,\text{jet}} > 50$ GeV veto for additional jets is applied is also shown (dot-dashed). Input parameters are defined in the main text.
• Figure 4: $ZZ$ invariant mass distribution for $ZZ$+jet production at the Tevatron and LHC with $\mu_R=\mu_F=M_Z$. The differential $K$ factor is also shown. The $K$-factor bands are defined in the main text. Other details as in Fig. \ref{['fig:scalevar']}.